KR20040001531A - Method for inspecting defect in plate wafer using laser marking process - Google Patents

Abstract

PURPOSE: A method for inspecting the defect of a plate type wafer using a laser marking process is provided to be capable of reducing the fabrication cost and time of the wafer and removing noise for improving sensitivity by assigning coordinates to the defects of the wafer. CONSTITUTION: More than two marks are formed on the surface of a plate type wafer(10) by carrying out a laser marking process using an SEM(Scanning Electron Microscope). A wafer scanning process is carried out by using an inspection tool located at the process line. The wafer is transferred to a predetermined equipment connected with the inspection tool. At this time, the scanning result is also transmitted to the predetermined equipment. After aligning the wafer by using the laser marking portion, defect coordinates are checked.

Description

Method for inspecting defect in plate wafer using laser marking process

The present invention relates to a method of manufacturing a semiconductor device using a laser marking process, and more particularly, to a method of investigating defects in a flat wafer using a laser marking process.

Defects present in flat wafers cannot be detected at high magnification using SEM, and low magnification using a microscope mounted on an inspection tool is not possible. Only investigation at is possible.

In such a case, it is difficult to distinguish precise and detailed defects and it is impossible to identify the cause of the defects.

In order to perform defect inspection at high magnification using SEM, a pattern wafer which undergoes one or more patterning (photo / etching) processes is required, which is expensive and time consuming.

In addition, in the case of pattern wafers, sensitivity may be lowered compared to flat wafers due to noise coming from the pattern.

Accordingly, the present invention has been made to solve the above problems of the prior art, by using artificial laser marking process to give artificial coordinates to the defects in the flat wafer can be investigated at high magnification using the SEM It is an object of the present invention to provide a method for investigating defects in a flat wafer using a laser marking process.

1 shows a flat wafer with a laser marking in accordance with the present invention.

[Description of Drawing Reference]

10 wafer 15 alignment / reference point

In order to achieve the above object, a method of investigating defects in a flat wafer using a laser marking process includes: marking two or more marks on the flat wafer using laser marking; Advancing the wafer to a process to examine for defects; Performing wafer scanning using an inspection tool present in the line; Bringing the wafer and the scanning results to the equipment connected to the irradiation tool; And performing wafer alignment using a laser marking display and identifying defect coordinates to be examined.

(Example)

Hereinafter, a method for investigating defects in a flat wafer using a laser marking process according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a flat wafer with a laser marking according to the present invention.

A method of irradiating a defect on a flat wafer by SEM using a laser marking process according to the present invention, as shown in FIG. 1, first, at least two or more on the flat wafer 10 using laser marking. Make a mark. At this time, the display position and number are adjustable, at least two markings are required for wafer alignment.

In addition, the laser marking marking is used as an irradiation tool and an alignment point 15 in the SEM.

Then, the wafer 10 is advanced to the process for examining defects. In this case, if the process to be irradiated is a post process, the marking of the laser marking may not be clearly seen. In this case, laser marking may be additionally performed after the dielectric deposition process performed before the process to be investigated.

Subsequently, wafer scanning is performed using an irradiation tool existing in the wiring. Depending on the performance of the irradiation tool and SEM equipment, an irradiation recipe can be prepared to recognize the flat wafer as a pattern wafer using laser marking.

If many defects at the edge are observed because the laser marking mark is close to the edge of the wafer, the laser marking mark is located off the edge of the wafer or the other edge portions except the laser marking mark are excluded from the scanning area.

The wafer and scanning results are then taken to the SEM equipment associated with the probe.

Subsequently, wafer alignment is performed using laser markings, and the coordinates of defects to be investigated are confirmed. At this time, the coordinates of the defects of relatively large size are found to check the position of the defect, and the offset is performed. If the FIB function exists in the actual equipment, the cross section of the defect can be observed using the FIB. have.

In addition, in the case of performing defect inspection at a high magnification of defects present in the flat wafer, a plane view of the defect is examined at high magnification using a CD SEM device, or a surface tilted at high magnification using a SEM device. You can check in the tilted view.

As described above, according to the method of irradiating the defects on the flat wafer with the SEM using the laser marking process according to the present invention, by applying artificial coordinates to the defects on the flat wafer using the laser marking process Defects present in the flat wafer can be investigated at high magnification using SEM.

In addition, by using a laser marking process, two or more marks on the flat wafer are processed, and after the process of examining defects is performed, a laser marking mark is used to enable wafer alignment and defect inspection in the SEM.

Therefore, the cause of the defect can be identified by investigating the defect in the flat wafer at high magnification through the SEM, which can bring about the effect of improving the yield.

In addition, the wafer fabrication cost and time can be reduced compared to the conventional SEM irradiation method using a patterned wafer.

In addition, the sensitivity can be improved by eliminating the noise from the pattern compared to the SEM irradiation method using the conventional pattern wafer.

On the other hand, the present invention is not limited to the above-described specific preferred embodiments, and various changes can be made by those skilled in the art without departing from the gist of the invention claimed in the claims. will be.

Claims (3)

Marking two or more marks on the flat wafer using laser marking; Advancing the wafer to a process to examine for defects; Performing wafer scanning using an inspection tool present in the line; Bringing the wafer and the scanning results to the equipment connected to the irradiation tool; And A method for investigating defects in a flat wafer using a laser marking process, comprising: performing a wafer alignment using a laser marking marking and identifying defect coordinates to be examined. The method of claim 1, wherein laser marking is additionally performed after the dielectric deposition process performed before the process to be irradiated. The method of claim 1, wherein the defect irradiation on the flat wafer is performed at high magnification by using a CD SEM device to investigate a plane view of the defect at high magnification or using a SEM device at high magnification. Method for investigating defects in a flat wafer using a laser marking process characterized in that for irradiating the defect cross section at a high magnification using irradiation or FIB equipment in a tilted view.